To create a larger vertical ground reaction force, you must perform the golf swing on the hardest surface possible.

Coefficient of Friction

To create a larger coefficient of friction, the bottom surface of the shoes that you are wearing must have 2 characteristics:

(1) the material of the soles must be soft

(2) the surface of the soles must be rough

Cleat Force

In the golf world, the word "spike" is synonymous with the world "cleat."

To create a larger spike force, the spikes attached to the bottom of your shoes must have 3 characteristics:

(1) the must be able to penetrate ground surface

(2) they must be long

(3) the must be wide

Muscle Force

To create a larger muscle force, three factors that influence the size of the muscle force must be considered.

(1) Muscle Size

-a muscle with a larger physiological cross-sectional area will create more muscle force

-increase via resistance training

(2) Muscle Length

-muscles stretched to 120% of their natural resting length generate the most muscle force

(3) Speed of the Muscle Contraction

-muscles that are concentrically contracted at slower speeds generate greater force than muscles that are concentrically contracted at faster speeds

Muscles Involved in Hitting a Golf Ball

SHOULDER GIRDLE ROTATION

Internal/External obliques

FOREARM SUPINATION

Biceps Brachii

Brachoradialis

Extensor Carpi Radialis Brevis

Extensor Carpi Radialis Longus

Supinator

SHOULDER ABDUCTION

Biceps Brachii

Deltoid

Pectoralis Major

HIP INTERNAL ROTATION

Adductor Brevis/Longus/Magnus

Gluteus Medius/Minimus

Gracilis

Pectineus

Semitendinosus

Semimembranosus

TFL

Moment Arm

The distance from the joint's axis of rotation to the line of pull of the muscle force.

To increase the moment arm distance, you would need to move the line of pull of the muscle force further away from the joint's axis of rotation.

One method for moving the line of pull of the muscle force would be to change the locations of the origin and insertion points for the muscle. It would be unethical to perform this type of surgery.

The only way we can change the moment arm distance is by changing the angle of the joint. When the long axes of the two bones connected at a joint are aligned long axis to long axis (straight line), the moment arm distance is the smallest.

Mass

SHORT-TERM

(1) wear the lightest clothing possible

(2) wear the lightest shoes possible

LONG-TERM

(1) lose fat mass

Radius of Resistance

The distance from the joint's axis of rotation to the center of mass of the body component.

Individuals with shorter bones will have shorter radii of resistance. There is nothing we can do to decrease bone length.

We can change the radius of resistance by changing the angles of the joints within the body component being rotated. We can decrease the radius of resistance by rotating the body component closer to the joint axis of rotation.

Application Time of Each Joint Torque

To increase the application time of the concentric shoulder girdle left rotation joint torque:

DURING THE PREP PHASE

the shoulder girdle must be right rotated

DURING THE EXECUTION PHASE

a concentric shoulder girdle left rotation joint torque is applied until the shoulder girdle is maximally left rotated.

To increase the application time of the concentric right forearm pronation joint torque:

DURING THE PREP PHASE

the right forearm must be supinated

DURING THE EXECUTION PHASE

a concentric right forearm pronation torque is applied until the right forearm is maximally pronated

To increase the application time of the concentric left forearm supination torque:

DURING THE PREP PHASE

the left forearm must be pronated

DURING THE EXECUTION PHASE

a concentric left forearm supination torque is applied until the left forearm is maximally supinated

To increase the application time of the concentric left shoulder abduction torque:

DURING THE PREP PHASE

the left shoulder must be adducted

DURING THE EXECUTION PHASE

a concentric left shoulder abduction torque is applied until the left shoulder is maximally abducted

To increase the application time of the concentric left hip internal rotation torque:

DURING THE PREP PHASE

the left hip must be externally rotated

DURING THE EXECUTION PHASE

a concentric left hip internal rotation torque is applied until the left hip is maximally, internally rotated

Radius of Rotation

The distance from the joint's axis of rotation to the point of interest on the body component.

Individuals with longer bones will have longer radii of resistance. There is nothing we can do to increase bone length.

We can change the radius of rotation by changing the angles of the joints within the body component being rotated. Any change in a joint angle that rotates a portion of the body component farther from the axis of rotation will lengthen the radius of rotation.